feat: install Playwright and create e2e directory structure

frontend/package.json

@@ -26,6 +26,7 @@
     "tesseract.js": "^7.0.0"
   },
   "devDependencies": {
+    "@playwright/test": "^1.40.0",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^16.0.0",
     "@testing-library/user-event": "^14.0.0",
@@ -33,6 +34,7 @@
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "@vitejs/plugin-react": "^4.0.0",
+    "@vitest/coverage-v8": "^1.6.1",
     "@vitest/ui": "^1.0.0",
     "eslint": "^9",
     "eslint-config-next": "15.0.0",